Method of making bags



April 26, 1938. vm 2,115,281

METHOD OF MAKING BAGS Filed April 5, 1934 IINVENTOR.

4 45 1%v ,M w

6 T ATTORNEYS.

Patented Apr. 26, 1938 METHOD F MAKING BAGS Adolph Potdevin, Garden City, N. Y., assignor to Potdevin Machine Company, Brooklyn, N. Y., a corporation of New York Application April 5, 1934, Serial No. 719,120

2 Claims.

This invention is directed to the production of bags, being more particularly directed to bags of cellophane, glassine and such materials as compared with paper bags.

In the bottoming of bags of the satchel bottom type flaps are provided at the bottom end of the bag which are employed in forming the bag bottom. This necessitates slitting of the bag material lengthwise of the bag tube, and with ma- .terials suchas cellophane and glassine and similar materials such slits are not satisfactory owing to the fact that when such materials are slit it is extremely difiicult to perform the bottoming operation without tearing the material. In the practice of the present invention I propose to prevent tearing of the material by slotting the material, the bottom of the slot being rounded or concaved, or I may slit the material providing a stop hole at the inner end of the slit. I have found that both'of these methods work much more satisfactorily than prior methods and, that tearing of the material is reduced to a minimum.

Two embodiments of my invention are shown in the accompanying drawing.

In the drawing:

Fig. 1 is a plan view of a bag tube showing the slots formed therein with a concaved or rounded bottom; while Figs. 2 and 3 show the next succeeding steps in 30 the forming of a bag bottom in such a tube;

' Fig. 4 is a plan view of the completed bottom;

In Fig. 5 I show a modification;

Fig. 6 shows the bag tube completely severed;

Fig. 7 is a plan view of the bottoming operation; and

Fig. 8 is a plan view showing the finished bottom.

Referring to the drawing in detail and first of all to the embodiment of my invention shown in 40 Figs. 1 to.4. The bag stock is designated 1, and as above mentioned is composed of cellophane, glassine or similar material as distinguished from paper. Th stock may be tubed by any of the methods used in the bag making art.

2 designates a bag length which severed from the tube.

It will be seen upon reference to Fig. 1 that the walls of the bottom end of the bag length 2 are slotted lengthwise at 3 and 4 the bottom of each 50 of these slots being rounded or concaved as shown at 5. These slots produce two flaps 5 and 1 at the bottom end of the bag length, the flap 6 projectln beyond the end of the bag length.

In the operation of bottoming the bag, which is illustrated in Figs. 2 and 3, it will be seen that has been the slotted end'of the bag length is opened and the wall having the flap l folded back upon the main body of the bag length as shown in Fig. 2. This necessitates deforming of the material of the bag length which is permitted by the slots 3 and 4. Due to the rounded bottom 5 of each of these slots this operation may be performed successfully, however, without tearing the material. I might mention that in the bottoming operation it is customary to effect opening of the bag length by gripping the flaps t and l and moving them away from each other so that considerable tension is imposed on the fragile material of the bag length, but as above set out despite this fact, the provision of the round bottom slots 3 and 4 enables the operation to be performed without tearing. After the tube has been opened up and folded backas illustrated, paste shown at 8 is applied, flap 1 folded down and the flap 6 folded over to complete the bottoming operation as shown in Fig. 4.

In Figs. 5, 6, 7 and 8 where Ihave illustrated a modification of the invention above described, the web 9 of cellophane, glassine or similar materials is punched to provide sets of holes l0 and 11 therein, as seen in Fig. 5. This is before tubing. The web is then tubed as shown in the same figure of the drawing, to bring the holes 10, which I will assume for purposes of descriptionare in the upper wall l2 of the tube, into approximate register with the holes H in the lower wall 13 of the tube. Both walls of the tube are next slit lengthwise as shown at M, the slits extending into the holes or perforations l0 and H.

The operations so far described are prior to the cutting-off operation. The stop-holes or perforations IO and H are formed before the web is tubed and when the web is tubed it is unnecessary'that the holes in one wall register precisely with those in the other wall as one slitter can be employed for slitting one wall and another slitter for the other wall, so that absolute accuracy is assured so far as the slits being properly aligned with the holes is concerned.

The tubing is next divided adjacent the ends of the slits 14, to provide a bag length with a flap 15 in one wall and a flap l6 in the other wall.

The bottoming operation is similar to that described in connection with Figs. 1 to 4, and it will be appreciated that the stop-holes or perforations will prevent tearing of the material during the deformation of the material incident to the bottoming operation as explained above.

From the foregoing it will be appreciated that I have provided a method for use in connection with the bottoming of bags wherein danger of tearing of the material during the bottoming operation is reduced to a minimum, the rounded bottom of the slots 3 and I and the stop-holes or perforations II) at the end of the slits ll effectively preventing such contingency.

What I claim is:-

1. In bag making, the method which comprises tubing the bag material, dividing the bag materialtransversely into bag lengths to provide a projecting flap on one wall of each bag length, and then preparing the leading end of the bag length for bottoming by removing a narrow longitudinal strip of the material from each wall of the bag length to provide slots adjacent the sides of said flaps, the bottom of said slots being concaved. 

